Hi @Nasute,
That's actually a fairly small dataset you are trying to denoise so it shouldn't take too long... of course that's dependent on your processor, how many cores you have available on your system etc.
What you are describing as 'locked up' is actually normal. As long as the last operation you entered is still running you won't be able to run any other. With the --verbose tag you'll see some more information as DADA2 is running but you still won't be able to perform any other operations (again, totally normal). Just let it run until it completes or perhaps you'll get an error which then we can trouble-shoot further.
Good luck!